Temperature control system



July 7, 1942.

R; L. ROLAND TEMPERATURE CONTROL SYSTEM Filed July 5, 1938 2 Sheets-Sheet 1 (MT/ML v CONT/ML BOX 4 a 30;

.8 45 F I A $WMW W R. L. ROLAND TEMPERATURE CONTROL SYSTEM Filed July 5, 1938 July 7, 1942.

I 2 Sheets-Sheet 2 use is indicated by good practice.

Patented July 7, 1942 OFFICE TEMPERATURE CONTROL SYSTEM Ralph L. Roland, Bloomington, 111.

Application July 5, 1938, Serial No. 217,330

This invention relates to a control system for regulating the heating and cooling of buildings and for maintaining them at the desired temperature. It is generally recognized by skilled heating engineers that proper temperature control of buildings is dependent upon the balance of several factors including outside weather and.

temperature, inside temperature, building tightness and insulation and the efiiciency of the heating and cooling equipment.

The principal object of my invention is to provide a system of controls which can be balanced in a manner that will result in substantially uniform interior temperatures in various kinds of buildings under widely variable conditions.

Another object is to provide a control system involving comparatively simple, sturdy control apparatus that may be easily installed, wired and adjusted by ordinary electricians guided by simple instructions.

Other objects and benefits will be disclosed in the following descriptions, illustrations and claims.

The drawings as shown are somewhat diagrammatic in form, and it will be understood that conventional variations in the structures are to be expected and are contemplated. As an example where electrical contacts are shown as simple contact points, snap action or mercury switches may be substituted when such Also friction of resistance contacts might be eliminated by the use of mercury tube resistance devices. The

drawings are for illustration only and I do not desire to be limited to the construction shown except as such limitations are opposed by the appended claims.

Now referring to the illustrations:

4 Claims.', (01. 257-3) Fig. is a-front elevation view of my single solenoid balance with the cover removed and showing the mechanical structure described in the specifications.

. Now referring to Fig. 1'. The numeral Ill generally designates my single solenoid balance thermostat for controlling an air conditioning, and cooling apparatus. The numeral H generally designates my double solenoid balance thermostat for controlling the heating apparatus. The numeral I2- generally designates a transformer for reducing standard incoming high voltage current to low voltage for easier and safer use. erally my outdoor thermostat with a resistance element controlled by a shifting contact. The

numeral l4 designates generally my heater thermostat with resistance element also controlled by shifting contact. The numeral [5 designates a motor driven heating apparatus of any conventional type and the numeral [5a a control box containing a conventional relay switch for the motor circuit. The numeral l6 designates an air cooling or conditioning unit of any conventional type and the numeral 16a the'control box for this unit. It is understood that standard motor current is fed into these control boxes and, switched off and on by conventional relay refrigeration unit [6.

Fig. 1 is a diagrammatic illustration otthe in- I stallation of, my control apparatus in a building structure as described in the specifications;

Fig. 3 is a side elevation view of my double solenoid balance complete in a box showing the adjustment arm and adjustment graduations; Fig. 4 is a side elevationsectional view of my single solenoid balance as it would appear on sec tlon line 4-4 on the center line of Fig. 5; and

Transformer I2 is connected to a volt or' any standard voltage. line through conductors l1 and I8. The secondary of this transformer is brought out at l9 and 20. The heat balance II (also shown in Fig. 2) has two solenoid coils 2i and 22. Working in these coils are armatures 23 and 24, connected to the secured to it, but this end of spring is free to move in arc of the contact 21 as it is held so byan arm that movesloosely on shaft at the same point 34. The other end of the bimetallic spring is secured at 34 to a bushing fitted loosely to a shaft at 34. The bushing also has an arm 36 attached (shown in Fig. 2) which is used to adjust the room temperature. Contacts 30 and 3| connect to the heating apparatus switch in con- The numeral l3 designates gen 30 and 3| are used when a three makes contact at 40 with the arm 49 on the bimetallic spring 4|, which is mounted on a bushing 4| and shaft 4|" at this point. Spring 4| is secured at point 42 to frame of the thermostat. Spring is connected by conductors 43 and 44 to the secondary lead |9 of the transformer l2.

The other solenoid 'coil 2| of the balance II is connectedat 41 to a conductor 48 thereby to the resistance 49 at 50. Resistance .49 makesco'ntact'at 5| with arm 63 which is attached to a bimetallic spring 54 at 55. The other end of the bimetallic spring is secured at 56 to the frame of the thermostat. The spring 54 is con-' nected to the secondary of the transformer l2 at l9 by conductor 44.

The air conditioning balance l (also shown in Fig. has a bimetallic spring 58, carrying on themovable end contacts 59 and 60 which are attached thereto but insulated from it. The .conductors GI and 62 attached to these contacts run to a conventional relay switch in the control box 1611 controlling currentto the motor leads 6| and 62' and, like balance ll, only 6| is used in circuit where a make and break contact is used and both when a three wire system is used. The other end of the spring 58 is fastened to a bushing moving on a shaft at 63. The bushing has an arm attached to adjust the room temperature. Fig. 5). The solenoid coil 65 having armature 65 connected to balance beam 61, which has arm 68 secured to it, which in turn has the'contact 69 attached. Contact 69 is attached to the con trol |6d through the conductor 10. The other end of the balance beam 61 has an adjustable tension spring 'Il attached, working against solenoid coil 65. The solenoid coil 65 is attached to conductor ",and conductor connecting to the secondary of the transformer I2 at 20. The other end of the solenoid coil leads through conductor'13 to thethermostat l3 and attaches to the resistance 14 at I5. Resistance 14 connects with the arm 53 which is secured to the bimetallic spring 54 at 55. Conductor 44 connects the bimetallic spring 55. to the secondary of the' transformer l2 at |9.

The heat' balance is so constructed that when the temperature on the outside of the building drops below 72 degrees the thermostat l3 goes into the heating cycle. 54 pulls arm 53 over into contact with the resistance 49 completing the circuit with the transformer secondary and the solenoid coil 2|. The current flows through coil 2| and the balance beam is moved .down by the armature 23, causing arm 26 to place contact 30 in touch with contact 21, starting-the heating apparatus to put This arm is 64 (shown only on' The bimetallic spring breaks contact with 30, thereby stopping the heat.

If the temperature outside of the building at the thermostat l3 drops more, the same process is gone through, giving more heat to the heating unit.

The heat at the thermostat |4 mustcut the resistance of 39 to match the amount cut by the cold at the thermostat I3 at 49, and at the same time satisfies the thermostatic action of the bi- I metallic spring of the balance When the temperature outside of the building at the thermostat l3 goes above '12 degrees arm 53 leaves resistance '49, thereby turning oif the heat and making contact with 14 which picks up the current of the transformer |2 through conductor- 44 and flows the current through solenoid coil 65 of balance It), pulling balance beam 61 down towards coil 65 moving arm 68 and contact 69 to contact 59 starting the air condition-. ing unit l6. s

When the room cools, the bimetallic spring 58 of the balance 10 pulls contact 60 over to 69;

, thereby breaking the contact with 59, the refrigerating unit is stopped. If a make and break contact all that is needed, theconductor 62 may be omitted and only used for a three wire system.-

As the temperature at the thermostat 3 rises, more resistance is cut off 14 by arm 53,. causing more current to flow through coil of the balance l0 causing contact 69 to move to the left which would permit the temperature of the room -to rise in proportion to the outside. This is not desired so spring 1| is so arranged that the tension will hold back this movement so that the room temperature will not rise as fast as the outside temperature.

I claim:

l. A temperature control apparatus for an enclosure having a heat source, said apparatus including a master thermostat within the enclosure, having a minimum limit electrical contact, a maximum limit electrical contact, energizing contacts shiftable between said minimum and maximum limit contacts, temperature-sensitive means to impart relative movement .to.

said contacts responsive to temperature variations within the enclosure, a manually shiftable adjustmentfor said contact, and an automatic compensating adjustment arranged to shift said contacts and alter the critical temperatures of the thermostat to raise the critical temperatures of the master thermostat in response to a decrease in temperature outside of the'enclosure, and to lower the critical temperatures of the thermostat responsive to an increase in the temperature of the heat source, said automatic compensating adjustment comprising an electromagnetic coil having' an armature, a second electro-magnetic coil having an armature 'mechanically coupled to the armature of the first coil and to the said contacts and arranged to out heat, which heats the bimetallic spring 4| of thermostat |4 moving the arm to the right, reducing the resistance of 39, causing more cur- "towards 3| where'it makes contact with 3| or shift the adjustment of the contacts, an outside compensating thermostat including a variable resistance electrically connected to one of the aforementioned electro-magnetic coils and mechanically coupled to a temperature-sensitive element to be actuated thereby to reduce the resistance responsive to a decreasein temperature; and a second compensating thermostat at the heat source including a variable resistance electrically coupled to the other of the aforementioned electro-magnetic coils-and mechanically coupled to a temperature-sensitive element to.

be actuated thereby to reduce the resistance responsive to increases in temperature of the heat source.

2. A temperature control apparatus for an enclosure having a heat source, said apparatus consisting of a master thermostat within the en-' closure and a pair of compensating thermostats; said master thermostat including a minimum limit electrical contact, a maximum limit electrical contact, energizing contacts shiftable be tween said minimum and maximum limit contacts, temperature-sensitive means to impart relative movement to said contacts responsive to temperature variations within the enclosure, a manually shiftable adjustment for said contacts, said compensating thermostats being arranged to vshift said contacts and alter the critical temperatures to raise the critical temperature of the master thermostat in response to a decreasein temperature outside of the enclosure, and to lower the critical temperatures of the thermostat responsive to an increase in the temperature of sensitive element to be actuated thereby to reduce the resistance responsive to increases in temperature of the heat source.

3. In a temperature control system for buildings, dual indoor space thermostats, a bi-metallic outdoor thermostat connected to dual electric circuits separated at the comfortable temperature point, dual resistance elements actuated by dual indoor space thermostats being a dual solenoid control thermostat for controlling the heating apparatus having one solenoid interconnected with said cold range resistance circuit, the other indoor space thermostat for controlling cooling and air conditioning apparatus interconnected with the hot range resistance circuit, a heater thermostat actuating a resistance element connected in circuit with the other of said dual solenoid elements, and a transformer having a low voltage circuit connecting said' contemperature point, dual resistance elements aosaid thermostat, one of said elements being actuated by said thermostat, one of said elements being actuated in the cold range setting of the thermostat to raise the setting of the space th rmostat and the other in the hot range setting to lower the setting of the space thermostats, one of said dual indoor space thermostats being a dual solenoid control thermostat for controlling the heating apparatus having one solenoid interconnected with said .cold range resistance circuit, the other indoor space thermostat for controlling cooling and air conditioning apparatus interconnected with the hot range resistance circuit, a heater bi-metalii'c thermostat actuating a resistance element connected in circuit with the other of said dual solenoid elements, and a transformer having a low voltage circuit connecting said control apparatuses thr0ugh relay switches tocontrol the power circuits where-v by the heating and cooling apparatuses are started and stopped to maintain desired interior temperatures by a balanced adjustment of the interconnected 4 control apparatuses.

, RALPH L. 

